March 22, 1996, 3:13:04 a.m. EST. Launch set for March 21 pending resolution of issue concerning wiper O-rings on nozzle-tocase joints on both Redesigned Solid Rocket Motors (RSRMs) flown on previous mission, STS-75. Different situation from STS- 71/STS-70 O-ring issue that occurred in 1995 and affected nozzle internal joint. STS-75 gas paths went through polysulfide adhesive to, but not past, wiper O-ring on nozzle-to-case joints. Similar gas paths observed on previous missions, but STS-75 marked first time two different gas paths observed in one nozzle-to-case joint, and on both RSRMs. After review, managers concluded nozzle-to-case joint design was robust and safe to fly, and launch preparations proceeded. First launch attempt set for March 21 scrubbed prior to commencement of tanking operations March 20, due to concerns about high winds. Launch reset for March 22 proceeded smoothly to on-time liftoff. During ascent, leak occurred in hydraulic system powered by Auxiliary Power Unit (APU) number 3. Leak stopped after hydraulic system shutdown on-orbit. Mission managers concluded system would remain stable and proceeded with plans for full-duration mission.

Landing:

March 31, 1996, 5:28:57 a.m. PST, Runway 22, Edwards Air Force Base, Calif. Rollout distance: 8,357 feet (2,547 meters). Rollout time: 55 seconds. Mission duration: nine days, five hours, 15 minutes, 53 seconds. Landed revolution 145. Mission managers re-scheduled landing from March 31 to March 30 in anticipation of rain and clouds at KSC landing site, but landing attempts at KSC March 30 and 31 waved off due to weather before orbiter finally diverted to California. More conservative weather criteria employed for landing due to leak in APU number 3 hydraulic system and special measures taken during re-entry to minimize use of this particular APU. Following waveoff March 30, payload bay door reopening process interrupted when release indicators for payload bay door centerline latches 9 through 12 on both sides failed to indicate release, suggesting latches had not operated properly. Astronauts ventured into SPACEHAB module in aft payload bay to visually inspect the latches, which appeared to have opened as intended. Crew used manual mode to complete opening of doors without further incident, and glitch attributed to microswitches. Also, during prelanding preparations, three of 38 Reaction Control System (RCS) thrusters failed, but backup thrusters were available to perform same functions. Not considered a night landing because it occurred 11 minutes before sunrise; flight rules define night launch/ landing as one occurring no earlier than 15 minutes after sunset and no later than 15 minutes before sunrise.

Mission Highlights:

Third linkup between U.S. Space Shuttle and Russian Space Station Mir highlighted by transfer of veteran astronaut Shannon Lucid to Mir to become first American woman to live on station. Her stay on Mir kicked off continuous U.S. presence in space for next two years.

Payload bay configuration included Orbiter Docking System in forward area and SPACEHAB single module toward the aft. STS- 76 marked first flight of SPACEHAB pressurized module to support Shuttle-Mir dockings; single module primarily served as stowage area for large supply of equipment slated for transfer to space station, but also carried European Space Agency's Biorack experiment rack for on-orbit research.

Atlantis hooked up with Mir on flight day 3, following same R-bar approach employed on STS-74. Actual connection between Orbiter Docking System and Docking Module attached to Kristall module docking port occurred at 9:34 p.m. EST, March 24. Hatches opened a little less than two hours later. Awaiting Atlantis' arrival were Mir 21 Commander Yuri Onufrienko and Flight Engineer Yuri Usachev, who were launched to Mir on Feb. 21. In August, they were joined by Mir 22 Commander Gennady Manakov, Flight Engineer Pavel Vinogradov and French Space Agency cosmonaut researcher Claudie Andre-Deshays.

After two-week stay Andre- Deshays returned to Earth with Onufrienko and Usachev while Manakov and Vinogradov remained on board with Lucid. During five days of docked operations, about 1,500 pounds (680 kilograms) of water and two tons of scientific equipment, logistical material and resupply items transferred to Mir; experiment samples and miscellaneous equipment brought over to orbiter. In Biorack, 11 separate scientific investigations were conducted. Study topics included effect of microgravity and cosmic radiation on plants, tissues, cells, bacteria and insects and effects of microgravity on bone loss. Also transferred to station were Mir Glovebox Stowage (MGBX) equipment to replenish glovebox already on station; Queen's University Experiment in Liquid Diffusion (QUELD) flown in orbiter middeck locker; and High Temperature Liquid Phase Sintering (LPS) experiment.

On flight day six, Godwin and Clifford conducted first U.S. extravehicular activity (EVA) around two mated spacecraft. During 6:02:28 EVA, they attached four Mir Environmental Effects Payload (MEEP) experiments to station's Docking Module. Experiments designed to characterize environment around Mir over an 18- month period. Two spacewalkers wore Simplified Aid For EVA Rescue (SAFER) propulsive devices first flight-tested during STS- 64.

Other payloads: Shuttle Amateur Radio Experiment (SAREX); KidSat, a project that gives middle school students opportunity to participate in space exploration; and Trapped Ions in Space (TRIS), a Naval Research Laboratory experiment flown in Get Away Special canister in cargo bay.

Atlantis American manned spaceplane. 33 launches, 1985.10.03 to 2011.07.08. The space shuttle Atlantis was the fourth orbiter to become operational at Kennedy Space Center, and the last of the original production run. More...

Mir The Mir space station was the last remnant of the once mighty Soviet space programme. It was built to last only five years, and was to have been composed of modules launched by Proton and Buran/Energia launch vehicles. These modules were derived from those originally designed by Chelomei in the 1960's for the Almaz military station programme. As the Soviet Union collapsed Mir stayed in orbit, but the final modules were years late and could only be completed with American financial assistance. Kept flying over a decade beyond its rated life, Mir proved a source of pride to the Russian people and proved the ability of their cosmonauts and engineers to improvise and keep operations going despite all manner of challenges and mishaps. More...

Associated Launch Sites

Cape Canaveral America's largest launch center, used for all manned launches. Today only six of the 40 launch complexes built here remain in use. Located at or near Cape Canaveral are the Kennedy Space Center on Merritt Island, used by NASA for Saturn V and Space Shuttle launches; Patrick AFB on Cape Canaveral itself, operated the US Department of Defense and handling most other launches; the commercial Spaceport Florida; the air-launched launch vehicle and missile Drop Zone off Mayport, Florida, located at 29.00 N 79.00 W, and an offshore submarine-launched ballistic missile launch area. All of these take advantage of the extensive down-range tracking facilities that once extended from the Cape, through the Caribbean, South Atlantic, and to South Africa and the Indian Ocean. More...